1. Field of the Invention
The present invention relates to a dealcoholation condensation type room temperature curable organopolysiloxane composition and particularly to a condensation type room temperature curable organopolysiloxane composition which is excellent in shelf stability in the uncured state.
2. Description of the Prior Art
As dealcoholation condensation type room temperature curable organopolysiloxane compositions, there are known those containing a diorganopolysiloxane terminated with hydroxyl group at both terminal ends of the molecular chain as the base component. In order to block the hydroxyl group at both terminal ends of the molecular chain of said diorganopolysiloxane, various kinds of alkoxysilanes are added to said compositions. When a reaction for the blocking proceeds, alcohol is released in the system and causes a problem of considerably lowering the shelf stability of said compositions.
In order to prevent the lowering of the shelf stability caused by the release of alcohol, it is known to use a diorganopolysiloxane previously blocked by an alkoxyl group at both terminal ends of the molecular chain. For example, as the dealcoholation type room temperature curable organopolysiloxane composition having the diorganopolysiloxane blocked by alkoxyl group, Japanese Patent Publication (KOKOKU) No. 1-113429 (1989) discloses a composition in which a tin compound is used as a catalyst, and Japanese Patent Publication (KOKOKU) No. 61-034063 (1986) discloses a low-modulus type composition in which an extending filler such as calcium carbonate and a small amount of a reinforcing filler are used in combination as fillers.
However, even in said compositions it is not achieved yet to improve the shelf stability thereof to a satisfactory level.